Iron deposition in the heart occurs in beta-thalassaemia major and contributes to cardiac dysfunction. Eighteen patients with beta-thalassaemia major were assessed clinically and had non-invasive investigations. They were young (15.5 +/- 3.6 years). Two patients had clinical heart failure. Doppler echocardiography demonstrated higher transmitral peak flow velocity in early and late diastole compared with controls (e: p<0.05, a: p<0.01). Transtricuspid peak late diastolic flow velocity was higher in patients (p<0.005). Isovolumic relaxation time was shortened (p<0.001). Pulmonary venous flow velocity was higher in diastole than systole (S: 0.51 +/- 0.11 m/s, D: 0.62 +/- 0.08 m/s). Reversal of pulmonary venous flow during atrial systole was seen in eight patients. These diastolic filling abnormalities did not significantly change with blood transfusion. Left ventricular ejection fraction was normal in patients. Two patients had cardiomegaly on chest X-ray. In beta-thalassaemia with iron overload, there is a restrictive pattern of diastolic dysfunction. This is not altered by recent blood transfusion. Left ventricular function remains relatively intact.
This study is conducted to investigate and compare image quality and radiation dose between prospective ECG-triggered and retrospective ECG-gated coronary CT angiography (CCTA) with the use of single-source CT (SSCT) and dual-source CT (DSCT).